maint: write-file-hooks -> before-save-hook write-file-hooks is obsolete since Emacs 22.1 (released June 2007) and it's time to use the recommended replacement. Problem reported by Glenn Morris in: https://lists.gnu.org/r/bug-gnulib/2018-03/msg00008.html * contrib/tap-driver.pl, lib/compile, lib/depcomp, lib/install-sh: * lib/mdate-sh, lib/missing, lib/mkinstalldirs, lib/py-compile: * lib/tap-driver.sh, lib/test-driver, lib/ylwrap: Update hook usage for files where Automake is the canonical source.